Well, the game developers (or someone on this site anyway) have led me to believe that your peeps will live longer if fed a diet of organic foods. Not too sure yet if that's actually a GOOD thing or not, lol! I really hate seeing them walk at such a slow pace, so when mine are old I really don't like to play them and basically only check in to make sure they still have food and to see if they've died yet. Aren't I terrible?